In December, MTVgave a script-to-series commitment to Shannara, a drama series based on Terry Brooks’ massive fantasy book series. Jon Favreau was set to direct and Smallville creators Al Gough and Miles Millar to write, marking one of the most ambitious moves on the network’s scripted side since since Susanne Daniels became president. Now the fantasy is a reality, with a twist: MTV has greenlighted 10 episodes of the series, but scheduling conflicts have forced Favreau to exit the director’s chair, with Teenage Mutant Ninja Turtles‘ director Jonathan Liebesman coming aboard to direct first two episodes. He also will have an executive producer credit.

Favreau will stay on as executive producer. Gough and Millar, who worked with Daniels at WB Network on Smallville, will write and executive produce along with Brooks and Dan Farah (The Crow remake), and Sonar Entertainment is producing with MTV and distributing worldwide. The greenlight is set to be announced today at MTV’s session at TCA.

Shannara features plenty of young-adult adventure and romance to suite MTV’s target demographic (it would be compatible with MTV’s only successful drama series so far, Teen Wolf, which also has supernatural elements). The books — originally set up as a feature film at Warner Bros — are set in our world, thousands of years after the destruction of our civilization. The story centers on the Shannara family, whose descendants are empowered with ancient magic and whose adventures continuously reshape the future of the world.

Producers plan to base the show’s first season on The Elfstones Of Shannara, the second title in the series and credited with setting the series’ place in the fantasy world. The first book in the series came out in 1977 and has spawned sequels, prequels and graphic novels, with the time-shifting and complexity of the series great enough that there’s even a page on Brooks’ website suggesting the best order in which to to read them.

Brooks is the second-biggest-selling living fantasy book writer after Harry Potter author J.K. Rowling, with the Shannara books estimated to be the highest-selling fantasy series in the world without a screen adaptation. Liebesman is repped by CAA and David Gardner at Principato Young.